This specification relates to data processing and information retrieval.
The Internet provides access to a wide variety of resources such as images, video or audio files, web pages for particular subjects, book articles, or news articles. These resources also include web pages, such as social networking web pages, that are provided by publishers and maintained by users. For example, the users can post (e.g., upload or select) content that the users want on their respective social networking web pages. Each user can also selectively control on a per-user or per-group basis, which other users are able to access at least a portion of the content that the user has posted to their social networking web page.